Generally, the hard disk drive (HDD) includes the suspension on which a magnetic head slider is mounted. In this case, the magnetic head slider is provided for writing and reading data relative to a disk adapted for storing data therein. The suspension includes the suspension substrate having a spring metallic layer and a plurality of (e.g., four to six) wirings, respectively layered on the spring metallic layer, via an insulating layer. With this configuration, by flowing or sending an electric signal through each wiring, the writing and reading of the data relative to the disk can be performed.
In recent years, it has been demanded to provide a more high-speed transmission line and increase the speed and amount of data processing. To this end, it is necessary to enhance the electric characteristics, such as impedance or the like, of the substrate.
In order to enhance such electric characteristics, one suspension substrate has been proposed, which includes a pair of wirings, each bifurcated into two wiring parts, via a bridge circuit, with the wiring parts bifurcated from one wiring being respectively arranged alternately to the wiring parts bifurcated from the other wiring (e.g., see JP 10-124837A).